Ciaran Johnston's [cj at nologic.org] 14 lines of wisdom included:
> If I type uptime, I get the load average printed onscreen, for 1, 5 and 15
> minutes. I can only assume that this is measured by taking a load
> "snapshot" at periodic intervals, and taking the average when uptime is
> called. If this is the case, is there any way of finding out the interval
> between snapshots? Or am I on the wrong track altogether?
The load average is calculated through the process scheduler.
The kernel uses "jiffies" or "ticks" as it's internal clock (roughly
1/100th of a second, but that's not accurate and can vary).
Basically a timer TIMER_BH interrupt is set, which goes off every N
jiffies or so and one of the side effects (wayyy down the line) is
to calculate the load. What the value of N is, I'm not sure and
can't find offhand, and would doubt if it's even constant.
This is from 2.2 kernels, 2.4 may have a completely different
interface.
Is there any particular reason you want the interval between load
average updates?
--
Philip Reynolds
RFC Networks tel: 01 8832063
www.rfc-networks.ie fax: 01 8832041
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